Introduction: New laser technologies including the 60W Thulium fiber laser (TFL) and 100W holmium laser with long pulse duration and stabilization mode (LPDSM) have been developed. Although these new technologies may fragment stones faster, they require greater capital expenditure. The purpose of this study was to compare the cost effectiveness of these new laser technologies and the conventional 30W holmium laser (HL) using a 1 cm upper pole kidney stone in a benchtop model.
Methods: Ten identical 1 cm BegoStones (CaOx monohydrate consistency) were placed into the upper pole calyx of a 3D printed kidney and treated by the same surgeon using a flexible ureteroscope. The kidney was attached to a 2x2 mm metal mesh and stones were fragmented until all pieces passed through the mesh. All stones were fragmented at 10W using a 272 µm fiber. The lasers tested included: A Soltive Premium 60W TFL, the Empower 100W HL with LPDSM and the Dornier 30W with no pulse modulation. The cost of the laser box, fibers, and the mean cost of OR time in California ($37/min) were used to compare cost effectiveness using an ANOVA test.
Results: Stone weights were similar between groups (p=0.422). Lasing time (13.6 vs. 19.8 vs. 24.0 min, p=0.000) and overall operating time (14.2 vs. 24.5 min vs. 44.3 min, p=0.000) were significantly lower in the TFL compared to the 100W HL with LPDSM and the 30W HL, respectively (Fig.1). The TFL and 100W HL with LPDSM required no fiber stripping, while the 30W HL required one fiber stripping. Compared to the 30W HL, the TFL and 100W HL with LPDSM resulted in cost savings of $1087.40 and $731.90 per case, respectively. When modeling cost, factoring in the original purchase price, the TFL and 100W HL with LPDSM became cost effective over the 30W HL after treating 83 and 81 stones, respectively. The Thulium laser was more cost effective compared to the 100W HL with LPDSM after 85 cases.
Conclusions: In this model the 60W Thulium laser was 67.8% faster than the 30W HL and 41.8% faster than the 100W Empower with long pulse duration and stone stabilization. The Thulium fiber laser will become cost effective after 83 and 85 cases over the 30W HL and 100W HL, respectively.